• 한국전기전자재료학회논문지
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• 제18권11호
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• pp.990-995
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• 2005

This paper reports the fabrication and characterization of $5\;\times\;5$ thermal cantilever array for nano-scaled memory device application. The $5\;\times\;5$ thermal cantilever array with integrated tip heater has been fabricated with MEMS technology on SOI wafer using 7 photo masking steps. All single-level cantilevers have a diode in order to eliminate any electrical cross-talk between adjacent tips. Electrical measurements of fabricated thermal cantilever away show its own thermal heating mechanism. Thermal heating is demonstrated by the reflow of coated photoresist on the cantilever array surface.

• 한국전기전자재료학회논문지
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• 제19권10호
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• pp.894-900
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• 2006

This paper reports the fabrication and characterization of $32{\times}32$ thermal cantilever array for nano-scaled memory device applications. The $32{\times}32$ thermal cantilever array with integrated tip heater has been fabricated with micro-electro-mechanical systems(MEMS) technology on silicon on insulator(SOI) wafer using 9 photo masking steps. All of single-level cantilevers(1,024 bits) have a p-n junction diode in order to eliminate any electrical cross-talk between adjacent cantilevers. Nonlinear electrical characteristic of fabricated thermal cantilever shows its own thermal heating mechanism. In addition, n-channel high-voltage MOSFET device is integrated on a wafer for embedding driver circuitry.

• 센서학회지
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• 제21권3호
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• pp.186-191
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• 2012

In this paper, we present a pH measurement method that uses a microcantilever-array-based biosensor system. It is composed of microcantilever array, liquid cell, micro syringe pump, laser diode array, position sensitive detector, data acquisition device, and data processing software. Four microcantilevers are functionalized with pH-sensitive MHA(mercaptohexadecanoic acid) as a probe, while three microcantilevers are functionalized with HDT(hexadecane thiol) as reference. We prepare PBS(phosphate buffered saline) solutions of different pH and inject them into the liquid cell with a predefined volumetric speed at regular time intervals. The functionalized mircocantilevers in the liquid cell deflect as a self-assembled monolayer on the microcantilever binds with probe molecules in the solution. The difference in deflection between the MHA-covered probe microcantilever and the HDT-covered reference microcantilever was used to compensate for thermal drift. The deflection difference clearly increases with increasing pH in the solution. It was shown that when the pH values of the PBS solutions are high, there were large variations in the deflection of microcantilevers, whereas there were small variations for low pH value. The experimental results show that the microcantilever array functionalized with MHA and HDT can detect pH value with good repeatability.

• Applied Science and Convergence Technology
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• 제23권4호
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• pp.161-168
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• 2014

A real-time monitoring of immersed antenna type inductively coupled plasma (ICP) was done with a homemade 2 dimensional voltage probe array to check the uniformity of the plasma. Measured voltage values with a high impedance voltmeter are close to the floating potential of the plasma. As the substrate carrier was moving into a magnetron sputtering plasma diffusive from a $125mm{\times}625mm$ size cathode, measured results showed reliably separation of plasma into the upper and lower empty space over the carrier. Infra red thermal imaging camera was used to observe the cross corner effect in situ without eroding a target to the end of the usage. 3 dimensional particle trace model was used to analyze the magnetron discharge's behavior.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2004년도 제29회 추계학술대회 발표논문집
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• pp.85-87
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• 2004

원격조정 아프터로딩 시스템에 사용하는 폴리에틸렌 삽입관에 금박을 입혀 라디오파(RF) 안테나로도 병행사용할수 있는 열 방사선 병용삽입관 을 제작하였다. 30W의 RF 전력으로 15분간 한천 판톰에 가열하였을 때 폴리에틸렌관은 약 5oC 상승하였으나 금박으로 코팅 된 폴리에틸렌관은 약 20${\circ}$C 상승하여 RF 안테나로 대용할 수가 있었다. 한천 팬텀 중앙부에 길이가 2 cm 인 4개의 전극을 1 cm 간격으로 정사각형이 되도록 삽입하여 가열하였을 때 90%등온곡선이 반경 1.25 cm 의 원형으로 균일하게 분포되었고 2 cm 간격으로 삽일 하였을 때 1.75 cm 반경으로 거의 4 각형의 균일한 분포를 얻었다. 개의 뇌 실질에 정방형의 중심을 43${\circ}$C로 50분간 온열 요법을 시행한 후 관찰한 조직병리학적 소견에서 의미있는 변화를 보였다.

• 한국안전학회지
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• 제10권4호
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• pp.9-12
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• 1995

Detection of small defects by medical ultrasonic testing when the thermal sprayed coating by $MoSi_2$ on the metal is done. The defects may occur at the bonded surface. So, the detecting method of the defects by non-destructive in spection is desired. Here, in order to examine the possibility of the detection of the small defects by the ultrasonic. The electronic scanning ultrasonic equipment using an array probe developed as the medical ultrasonic diagnostic equipment is applied for the detection of the metal material defects. It's validity is investigated.

• 천문학회보
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• 제40권2호
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• pp.31.1-31.1
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• 2015

For probing magnetic fields in the universe, rotation measure (RM) have been often used. RM allows us to obtain the information of integrated (or averaged) magnetic fields along a line of sight (LOS). On the other hand, the new technique so-called Faraday tomography will be used in practical in the near future thanks to the wide-band polarimetry by Square kilometre Array and/or its precursors. The technique allows us to obtain so-called Faraday dispersion function (FDF). FDF is the distribution function of magnetic fields and polarized sources along a LOS. Because of this fact, it is expected that the studies of magnetic fields associated with various astronomical objects will progress dramatically. Since FDF also includes information of cosmic-rays and thermal electrons, the investigation of FDF may advance the studies of dynamics of external galaxies and/or the star formation activities. We have studied the potentials of Faraday tomography such as a tool to probe the intergalactic magnetic field associated with filaments of galaxies in the large scale structure. We have also studied the realistic FDFs of galaxies for understanding global magnetic field, cosmic-ray and thermal electrons of external galaxies. In the talk, we briefly introduce the Faraday tomography technique and report the results related to the Faraday tomography.

• 천문학논총
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• 제30권2호
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• pp.133-137
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• 2015

The Galactic center uniquely provides opportunities to resolve how star clusters form in neutral gas overdensities engulfed in a large-scale accretion flow. We have performed sensitive Green Bank 100m Telescope (GBT), Karl G. Jansky Very Large Array (JVLA), and Submillimeter Array (SMA) mapping observations of molecular gas and thermal dust emission surrounding the Galaxy's supermassive black hole (SMBH) Sgr $A^{\ast}$. We resolved several molecular gas streams orbiting the center on ${\gtrsim}10$ pc scales. Some of these gas streams appear connected to the well-known 2-4 pc scale molecular circumnuclear disk (CND). The CND may be the tidally trapped inner part of the large-scale accretion flow, which incorporates inflow via exterior gas filaments/arms, and ultimately feeds gas toward Sgr $A^{\ast}$. Our high resolution GBT+JVLA $NH_3$ images and SMA+JCMT 0.86 mm dust continuum image consistently reveal abundant dense molecular clumps in this region. These gas clumps are characterized by ${\gtrsim}100$ times higher virial masses than the derived molecular gas masses based on 0.86 mm dust continuum emission. In addition, Class I $CH_3OH$ masers and some $H_2O$ masers are observed to be well associated with the dense clumps. We propose that the resolved gas clumps may be pressurized gas reservoirs for feeding the formation of 1-10 solar-mass stars. These sources may be the most promising candidates for ALMA to probe the process of high-mass star-formation in the Galactic center.

• 대한의용생체공학회:의공학회지
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• 제43권3호
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• pp.147-152
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• 2022

This research is to measure real-time temperature distribution inside a tissue-mimicking phantom for the safety and effectiveness evaluations of focused ultrasound (FUS) device capable of linear scanning stimulation. Since the focusing area of the FUS stimulation device is smaller than diameter of conventional thermal probe and keeps moving, it is impossible to monitor temperature distribution inside the phantom. By using the phantom with a thin film temperature sensor array inserted, real-time temperature change caused by the FUS device was measured. The translation of the measured temperature peak was also tracked successfully. The present phantom had been experimentally proven to be applicable to validate the performance and safety of the therapeutic ultrasound devices.

• 한국방사선학회논문지
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• 제11권7호
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• pp.571-578
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• 2017

원자로 내 사고발생 시 냉각수의 비등으로 기포가 발생하고, 기포율을 측정하기 위하여 열수력 안전 분야에서는 주로 Optical Fiber Probe(OFP)나 광학 카메라를 이용하여 측정하지만 기하학적 구조의 한계로 인해 $17{\times}17$ 배열의 봉 다발 내에 장비를 설치하는 것에는 어려움이 있다. 본 연구는 예비 연구로서 봉 다발에 적용하기 전 X선 시스템과 다양한 모사 팬텀을 이용하여 연구 가능성 평가를 수행하였다. 라디오그라피 및 토모그라피 실험을 통해 X선 발생 장치의 관전압 130 kVp, 관전류 1 mA가 적합하였다. 또한, 기포 해상도 팬텀을 통해 가시적으로 1 mm 크기의 구멍에 대해 측정이 가능하였으며 막대 팬텀을 이용한 대조도 평가의 경우 프레온 내부에서 대조도가 상대적으로 떨어짐을 확인할 수 있었다. 그러나 영상 재구성 시 일그러짐이 없는 좋은 영상을 획득할 수 있었다. 기포 발생 팬텀 실험을 통해 기포의 유동 방향 확인 및 단층 영상을 획득할 수 있었고, Image J 툴을 이용하여 하나의 단층영상에 대해 18 %의 기포율을 측정할 수 있었다. 본 연구는 핵연료 주변 기포율 측정을 위한 선행 연구를 수행하였고 지속적인 연구를 위한 기초 연구로서 활용할 수 있을 것이다.